1. Field of the Invention
The present invention relates to a document scanning apparatus which scans information on just one side of the document.
2. Description of the Prior Art
Certain document scanning apparatus optically scans in a document, digitizes the document image and stores the digitized image signals or transmits them to a host computer. The ability to thus process the document image data in the form of electrical signals facilitates the speedy storage, retrieval, duplication and transmission of large quantities of such image data. Document scanners of this type are being developed to meet modern society's need for high-speed processing of growing quantities of information.
Conventional document scanning apparatus usually consist of a document feed section, a document optical scanning section and a document eject section. In a typical arrangement, a quantity of documents are stacked in the feeder section. These documents are then fed one at a time to the scanning section. At the scanning section the document is scanned by a beam of light and the light reflecting from the document is detected by an optical sensor such as, for example, a charge-coupled device (CCD), which digitizes the stream of image data. After being scanned the document is then ejected from the apparatus.
The trend is toward faster document scanners able to process large quantities of documents. However, stacks of documents to be processed often include some documents which are upside down, but with conventional scanning systems the image information on such upside-down documents will be lost. This has led to a need for a high-volume document scanning system that is also able to scan in information from upsidedown documents.
Conventionally, such loss of information from upside-down documents is prevented by manually ensuring that all the documents are stacked the right way up prior to feeding them into the scanner. This, however, works against the need to be able to speedily process large numbers of documents, and also takes time and labor.
Another technique is to employ a scanner that simultaneously scans both sides of the documents. However, as such systems reproduce images of the two sides of each document, in the case of documents which have information on one side only this system leads to half of the reproduction media being used to reproduce the non-information side of the documents, which is wasteful.